Investments in Unconsolidated Joint Ventures (Details 4) (Gramercy Property Trust Inc., USD $) Share data in Millions, unless otherwise specified		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended
	Jun. 30, 2013	Mar. 31, 2013 First Gramercy lease	Jun. 30, 2013 First Gramercy lease sqft	Mar. 31, 2013 Second Gramercy lease	Jun. 30, 2013 Second Gramercy lease sqft	Mar. 31, 2013 New Gramercy lease	Jun. 30, 2012 New Gramercy lease sqft	Mar. 31, 2013 Third Gramercy lease	Jun. 30, 2013 Third Gramercy lease sqft
Related Party Transactions
Shares held of Gramercy's common stock	0.7
Percentage of Gramercy's common stock owned	1.35%
Total investment in Gramercy based on market value of common stock	$ 3,400,000
Space leased (in square feet)			7,300		900		8,100		1,400
Annual lease rent for year one		249,000		35,300		345,000		67,300
Annual lease rent for year ten		315,000
Annual lease rent for year six				42,800				80,500
Annual lease rent for year three						$ 357,000